Retraction force sensing basket

ABSTRACT

A stone retrieval device includes a sheath and a stone retrieval basket that includes a distal region with a plurality of basket wires and a proximal region with one or more core wires. The stone retrieval basket is contained within the sheath and is movable out a distal opening of the sheath to cause the plurality of basket wires to open into a basket shape. The stone retrieval device further includes a lock mechanism that locks the position of the stone retrieval basket with respect to the position of the sheath and a basket force controller that includes a first control stage and a second control stage. The first control stage includes a sensor for measuring force on the stone retrieval basket when the lock mechanism is in an unlocked position, and the second control stage includes a sensor for measuring force on the stone retrieval basket when the lock mechanism is in a locked position. The stone retrieval device further includes an automatic release mechanism that releases the stone retrieval basket when the force on the stone retrieval basket exceeds a predetermined maximum force.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 62/184,623, filed on Jun. 25, 2015, the entire contentsof which are incorporated herein by reference.

FIELD

The present disclosure relates to a medical device. More specifically,the present disclosure relates to a medical device for capturing one ormore stone fragments.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may or may not constitute priorart.

During ureteroscopy or percutaneous nephrolithotomy (PCNL) procedures,baskets are often employed to capture and retrieve stone fragments froma patient's anatomy. After the stone fragments have been removed fromthe patient and released from the basket, the basket is re-inserted oneor more times into the patient's anatomy to remove all or most of theremaining stone fragments. In some instances, however, stone fragmentsthat are too large are captured in the basket, which may result in thebasket getting stuck in the ureter or access sheath. If the basket canbe pushed back, some fragments can be released and the basket can thenbe pulled out of the patient. If the basket is completely stuck, thebasket can be cut apart from the basket handle and sheath, or a smalllaser fiber may be inserted into the patient so that laser energy can beutilized to break up the stone fragments. In any case, if the basket isdamaged, a new basket has to be employed to complete the medicalprocedure, which may increase the surgical time and costs.

Among the literature that can pertain to this technology include thefollowing patent documents and published patent applications: U.S. Pat.No. 7,645,283, U.S. Pat. No. 5,944,728, US 2005/0261705, and DE69828984,the entire contents of which are incorporated herein by reference forall purposes.

Accordingly, to reduce surgical cost and time, there is a need for astone retrieval device that prevents the basket from getting stuck inthe ureter to minimize trauma to the ureter during retrieval of stonefragments.

SUMMARY

The present invention provides an improved medical device for capturingone or more stone fragments and a method of using such a device.

In one aspect, a stone retrieval device includes a sheath and a stoneretrieval basket that includes a distal region with a plurality ofbasket wires and a proximal region with one or more core wires. Thestone retrieval basket is contained within the sheath and is movable outa distal opening of the sheath to cause the plurality of basket wires toopen into a basket shape. The stone retrieval device further includes alock mechanism that locks the position of the stone retrieval basketwith respect to the position of the sheath and a basket force controllerthat includes a first control stage and a second control stage. Thefirst control stage includes a sensor for measuring force on the stoneretrieval basket when the lock mechanism is in an unlocked position, andthe second control stage includes a sensor for measuring force on thestone retrieval basket when the lock mechanism is in a locked position.The stone retrieval device further includes an automatic releasemechanism that releases the stone retrieval basket when the force on thestone retrieval basket exceeds a predetermined maximum force.

The stone retrieval device may be further characterized by one or anycombination of the features described herein, such as, for example: thelock mechanism is a ratchet mechanism; the ratchet mechanism includes afirst protrusion associated with a first member and a set of notchesassociated with a second member, the first member being contained in thesecond member and movable relative to the second member, the firstprotrusion being engaged with one notch of the set of notches when thelock mechanism is in the locked position; the one or more core wires isattached to a third member contained in the first member, the thirdmember being movable relative to the first member and including a secondprotrusion, the second protrusion being engaged with the firstprotrusion when the lock mechanism is in the locked position; movementof the third member relative to the first member pulls the plurality ofbasket wires into the distal opening of the sheath; the first controlstage sensor is a visual indicator with a first color; the secondcontrol stage sensor is a visual indicator with a second color that isdifferent than the first color; at least one of the sensors of the firstcontrol stage and the second control stage is a pop-up flag; at leastone of the sensors of the first control stage and the second controlstage is a tactile sensor; at least one of the sensors of the firstcontrol stage and the second control stage is a sonic sensor; and theautomatic release mechanism is resettable after releasing the stoneretrieval basket.

In another aspect, the present disclosure provides a method ofdetermining a force on a stone retrieval basket including one or more ofthe following steps: capturing a stone with the stone retrieval basket;and utilizing a sensor to determine if the force on the stone retrievalbasket exceeds a predetermined maximum force. The method may be furthercharacterized by one or any combination of the features describedherein, such as, for example: the sensor is visual sensor; and themethod further includes releasing the stone retrieval basket when theforce on the stone retrieval basket exceeds the predetermined maximumforce.

In yet another aspect, a stone retrieval device includes a sheath and astone retrieval basket that includes a distal region with a plurality ofbasket wires and a proximal region with one or more core wires. Thestone retrieval basket is contained within the sheath and is movable outof a distal opening of the sheath to cause the plurality of basket wiresto open into a basket shape. The stone retrieval device further includesa lock mechanism that locks the position of the stone retrieval basketwith respect to the position of the sheath.

The lock mechanism includes a first protrusion associated with a firstmember and a set of notches associated with a second member. The firstmember is contained in the second member and is movable relative to thesecond member. The first protrusion is engaged with one notch of the setof notches when the lock mechanism is in the locked position. The one ormore core wires is attached to a third member contained in the firstmember, and the third member is movable relative to the first member andincludes a second protrusion that is engaged with the first protrusionwhen the lock mechanism is in the locked position. The stone retrievaldevice also includes a basket force controller with a first controlstage and a second control stage. The first control stage includes asensor for measuring force on the stone retrieval basket when the lockmechanism is in an unlocked position and the second control stageincludes a sensor for measuring force on the stone retrieval basket whenthe lock mechanism is in a locked position.

Further features, advantages, and areas of applicability will becomeapparent from the description provided herein. It should be understoodthat the description and specific examples are intended for purposes ofillustration only and are not intended to limit the scope of the presentdisclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.The components in the figures are not necessarily to scale, emphasisinstead being placed upon illustrating the principles of the invention.Moreover, in the figures, like reference numerals designatecorresponding parts throughout the views. In the drawings:

FIG. 1 is side cross-sectional view of a stone retrieval device inaccordance with the principles of the present invention;

FIG. 2 is a side cross-sectional view of the stone retrieval deviceshown in FIG. 1 when the device is in a locked position;

FIG. 3 is a side cross-sectional view of the stone retrieval deviceshown in FIG. 1 when the device is applying a maximum pull force on oneor more stone fragments; and

FIG. 4 is a partial cross-sectional view of a basket device employedwith the stone retrieval device shown in FIG. 1 in accordance with theprinciples of the present invention.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.

Referring now to the drawings, a stone retrieval device embodying theprinciples of the present invention is illustrated in FIGS. 1 through 3and designated at 10. The stone retrieval device 10 includes a housing12, a first member 14 contained within a space 15 of the housing 12, asecond member 16 contained within a space 17 the first member 14, and athird member 26 contained within a space 27 the second member 16. Thethird member 26 includes an enlarged portion 28 and a smaller portion30.

The third member 26 is able to slide back and forth within the secondmember 16, and a protrusion 32 embedded in the enlarged portion 28selectively engages with a protrusion 34 embedded in the second member16. A biasing member 38, such as, for example, a coiled spring, ispositioned about the smaller portion 30. The biasing member 38 isarranged to urge the third member 26 away from an opening 29 of thesecond member 16.

The second member 16 is arranged to slide back and forth within thespace 17 of the first member 14. The protrusion 34 extends outwardlyfrom the second member 16 such that the protrusion 34 selectivelyengages with a notch of a set of notches 36 located on an inner surfaceof the first member 14. Hence, engagement of the protrusion 32 with theprotrusion 34 and engagement of the protrusion 34 with one of thenotches of the set of notches 36 operates as a ratchet or lockingmechanism to lock the position of the third member 26 and the secondmember 16 relative to the first member 14 in a locked position. When theprotrusion 34 is unengaged with any of the notches of the set of notches36. The second member 16, and consequently, the third member 26, are inan unlocked position relative to the first member 14.

A positioner 18 includes an extension 22 that extends through an opening24 of the housing 12 and an opening 25 of the first member 14. Theextension 22 is attached to the second member 16. An operator of thestone retrieval device 10, such as a physician, can therefore place, forexample, a thumb on an indentation 20 of the positioner 18 and push orpull on the positioner 18 to move the second member 16 relative to thefirst member 14 and the housing 12.

In certain arrangements, the stone retrieval device 10 includes a sensorsuch as, for example, a pull-force sensor with an opening 44 associatedwith the housing 12 and a set of color indicators 45 embedded in anenlarged portion 40 of the first member 14 that the operator can viewthrough the opening 44. Accordingly, as the first member 14 slideswithin the space 15 of the housing 12. Different colored indicators ofthe set of indicators 45 are observed through the opening 44. Anotherbiasing member such as, for example, a coiled spring 42 is positionedabout an extension 56 that extends from the enlarged portion 40 of thefirst member 14. The biasing member 42 is arranged to urge the firstmember 14 away from an opening 41 of the housing 12.

In various arrangements, the stone retrieval device is attached orconnected to a capturing device 50, which is shown in greater detail inFIG. 4. The capturing device 50, further a capturing basket 76, ispositioned within the sheath 52 and an optional expandable cone 68. Thecapturing basket 76 includes a rod or wire 54 with a distal end 66 and aproximal end 67 attached to the smaller portion 30 of the first member26. A pair of wires 58 and 60 are attached to the distal end 66 of therod or wire 54. Specifically, the ends of each of the wires 58 and 60are attached to the distal end 66 such that the mid region of the wires58 and 60 intersect at the distal most end of the capturing basket 76.As shown in FIG. 4, the wires 58 and 60 are generally orthogonal to eachother at the distal point of intersection for this particulararrangement. It is contemplated that various alternative basket wireconfigurations would work with the retraction force sensing handleportion of the present invention.

In addition to surrounding the rod or wire 54, the proximal region ofthe sheath 52 extends through the opening 41 of the housing 12,surrounds the extension 56 and is positioned within the coiled spring42. The sheath 52 is attached or connected to the enlarged portion 40 ofthe first member 14. Thus, movement of the third member 26 relative tothe first member 14 results in movement of the rod or wire 54 relativeto the sheath 52. Different color indicators of the set of colorindicators 45 viewed through the opening 44 indicates the pull force onthe capturing basket 76. Rather than color indicators, the pull-forcesensor can be a sonic sensor, a tactile sensor, a pop-up flag or anyother suitable sensor that indicates the pull force on the capturingbasket 76.

When the capturing device 50 includes the optional cone 68, thecapturing basket 76 is initially collapsed within the cone 68 as thecapturing device 50 is inserted into an anatomical region of a patient.After the capturing basket 76 and the cone 68 have been positioned inthe anatomical region containing stone fragments, the operator of thestone retrieval device 10 pushes on the positioner 18 distally such thatthe wires 58 and 60 exit a distal end 62 of the expandable cone 68. Itis contemplated that capturing basket 76 may alternatively extend from asheath without a cone extending therefrom at a distal end. It iscontemplated that a distal end of sheath may have a diameter equal tothe diameter of the sheath along its length. After the stone fragments70 have been captured by the wires 58 and 60, the operator pulls on thepositioner 18 proximally to draw the stone fragments 70 into the cone68, which causes the cone 68 to expand. The distal end 62 of the cone 68is configured to expand to a maximum predetermined size.

As the operator of the stone retrieval device 10 pulls the positioner 18distally, the second member 16 moves proximally relative to the firstmember 16 such that the protrusion 34 eventually engages with one of thenotches of the set of notches 36 associated the first member 14.Further, the proximal movement of the second member 14 also results inmovement of the second member 14 relative to the third member 26. Suchmovement results in engagement of the protrusion 34 with the protrusion32 embedded in the third member 26 and compression of the coiled spring38. As described earlier, engagement of the protrusion 34 with theprotrusion 36 and with one of the notches of the set of notches 36 locksthe third member 26 and the second member 16 with the first member 14 ina locked position (FIG. 2). To unlock the members, the operator pusheson the positioner 18 such that the protrusion 34 becomes unlocked fromthe set of notches 36 and the coiled spring 38 pushes the third member26 proximally relative to the second member 16 to unengage theprotrusion 34 from the protrusion 32.

During the stone removal procedure, the operator can view the colorindicators 45 through the opening 44. A first color indicator, such as alight color, can indicate to the operator that the pull force on thestone fragments 70 with not cause trauma or damage to the patient'sureter. As the operator pulls on the housing 12 when the stone retrievaldevice is in the locked positions, the operator continues to view thecolor indicators 45 through the opening 44. Additional pull force movesthe first member 14 distally relative to the housing 12, resulting incompression of the coiled spring 42 and movement of the set of colorindicators 45 relative to the opening 44. A second color indicator, suchas a darker color, may serve as a warning to the operator that the pullforce on the stone fragments is approaching a maximum limit. A thirdcolor indicator, such as a darkest color of the set of color indicators,may indicate to the operator that the pulls force is at the maximumlimit and any additional pull force may damage the patient's ureter.Reducing the pull force results in the coiled spring 42 pushing thefirst member proximally relative to the housing 12 such that the lightercolored indicators of the set of indicators 45 are viewed through theopening 44 to indicate to the operator that the pull force on thecapturing basket 76 has been reduced to a desired level.

The description of the invention is merely exemplary in nature andvariations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

What is claimed is:
 1. A stone retrieval device comprising: a sheath; astone retrieval basket including a distal region with a plurality ofbasket wires and a proximal region with one or more core wires, thestone retrieval basket being contained within the sheath and movable outof a distal opening of the sheath to cause the plurality of basket wiresto open into a basket shape; a lock mechanism for locking the positionof the stone retrieval basket with respect to the position of thesheath; a basket force controller including a first control stage and asecond control stage, the first control stage including a sensor formeasuring force on the stone retrieval basket when the lock mechanism isin an unlocked position and the second control stage including a sensorfor measuring force on the stone retrieval basket when the lockmechanism is in a locked position; and an automatic release mechanismthat releases the stone retrieval basket when the force on the stoneretrieval basket exceeds a predetermined maximum force.
 2. The stoneretrieval device of claim 1 wherein the lock mechanism is a ratchetmechanism.
 3. The stone retrieval device of claim 2 wherein the ratchetmechanism includes a first protrusion associated with a first member anda set of notches associated with a second member, the first member beingcontained in the second member and movable relative to the secondmember, the first protrusion being engaged with one notch of the set ofnotches when the lock mechanism is in the locked position.
 4. The stoneretrieval device of claim 3 wherein the one or more core wires isattached to a third member contained in the first member, the thirdmember being movable relative to the first member and including a secondprotrusion, the second protrusion being engaged with the firstprotrusion when the lock mechanism is in the locked position.
 5. Thestone retrieval device of claim 4 wherein movement of the third memberrelative to the first member pulls the plurality of basket wires intothe distal opening of the sheath.
 6. The stone retrieval device of claim1 wherein the first control stage sensor is a visual indicator with afirst color.
 7. The stone retrieval device of claim 6 wherein the secondcontrol stage sensor is a visual indicator with a second color that isdifferent than the first color.
 8. The stone retrieval device of claim 1wherein at least one of the sensors of the first control stage and thesecond control stage is a pop-up flag.
 9. The stone retrieval device ofclaim 1 wherein at least one of the sensors of the first control stageand the second control stage is a tactile sensor.
 10. The stoneretrieval device of claim 1 wherein at least one of the sensors of thefirst control stage and the second control stage is a sonic sensor. 11.The stone retrieval device of claim 1 wherein the automatic releasemechanism is resettable after releasing the stone retrieval basket. 12.A method of determining a force on a stone retrieval basket comprising:capturing a stone with the stone retrieval basket; and utilizing asensor to determine if the force on the stone retrieval basket exceeds apredetermined maximum force.
 13. The method of claim 12 wherein thesensor is visual sensor.
 14. The method of claim 12 further comprisingreleasing the stone retrieval basket when the force on the stoneretrieval basket exceeds the predetermined maximum force.
 15. A stoneretrieval device comprising: a sheath; a stone retrieval basketincluding a distal region with a plurality of basket wires and aproximal region with one or more core wires, the stone retrieval basketbeing contained within the sheath and movable out of a distal opening ofthe sheath to cause the plurality of basket wires to open into a basketshape; a lock mechanism for locking the position of the stone retrievalbasket with respect to the position of the sheath, the lock mechanismincluding a first protrusion associated with a first member and a set ofnotches associated with a second member, the first member beingcontained in the second member and movable relative to the secondmember, the first protrusion being engaged with one notch of the set ofnotches when the lock mechanism is in the locked position, the one ormore core wires being attached to a third member contained in the firstmember, the third member being movable relative to the first member andincluding a second protrusion, the second protrusion being engaged withthe first protrusion when the lock mechanism is in the locked position;and a basket force controller including a first control stage and asecond control stage, the first control stage including a sensor formeasuring force on the stone retrieval basket when the lock mechanism isin an unlocked position and the second control stage including a sensorfor measuring force on the stone retrieval basket when the lockmechanism is in a locked position.